ConditionalRestriction

The ConditionalRestriction library offers functionality for parsing and evaluating of conditional restriction values (see OSM Wiki).

This module offers functions suitable for most basic use cases.

Documentation

needsData :: String -> Result ErrorMsg [(ID, Type)]

Takes a conditional restriction string and returns the data needed in order to evaluate this string. If the conditional restriction couldn't be parsed, an error message is returned instead.

evaluate :: String -> [(ID, String)] -> Result ([ErrorMsg], [(ID, Type)]) (Maybe Token)

Takes a conditional restriction string and some input data. It returns the value as a token if any restriction condition was met, or Nothing otherwise. If there was a parsing error or a problem with the provided data, a list of error messages and a list of needed data is returned.

parseRestriction :: String -> Result ErrorMsg ConditionalRestriction

Takes a conditional restriction string and returns the corresponding AST. Take a look at the ConditionalRestriction.Parse.AST module for AST manipulation.

type ID = String

An identifier, identifying a value, e.g. "weight".

data Value

Input data value, corresponding to input Types.

Constructors

VBool Bool

Boolean value, e.g. "true".

VNum Double

Number value, e.g. "3.0".

VTime DateTime

Time value, e.g. "2022-05-10 18:00".

Instances

Show Value

Defined in ConditionalRestriction.Parse.InputData

Methods

showsPrec :: Int -> Value -> ShowS

show :: Value -> String

showList :: [Value] -> ShowS

Eq Value

Defined in ConditionalRestriction.Parse.InputData

Methods

(==) :: Value -> Value -> Bool

(/=) :: Value -> Value -> Bool

data Type

Input data type.

Constructors

TBool

Boolean type, e.g. value "true".

TNum

Number type, e.g. value "3.0".

TTime

Time type, e.g. value "2022-05-10 18:00".

Instances

Show Type

Defined in ConditionalRestriction.Parse.InputData

Methods

showsPrec :: Int -> Type -> ShowS

show :: Type -> String

showList :: [Type] -> ShowS

Eq Type

Defined in ConditionalRestriction.Parse.InputData

Methods

(==) :: Type -> Type -> Bool

(/=) :: Type -> Type -> Bool

type Token = String

A single token. Is used to represent values of any kind that the parser does not touch.

data Result e a

The Result type consists of an error type e and a success type a.

Constructors

Err e

Ok a

Instances

Bifunctor Result

Defined in ConditionalRestriction.Result

Methods

bimap :: (a -> b) -> (c -> d) -> Result a c -> Result b d

first :: (a -> b) -> Result a c -> Result b c

second :: (b -> c) -> Result a b -> Result a c

Applicative (Result e)

Defined in ConditionalRestriction.Result

Methods

pure :: a -> Result e a

(<*>) :: Result e (a -> b) -> Result e a -> Result e b

liftA2 :: (a -> b -> c) -> Result e a -> Result e b -> Result e c

(*>) :: Result e a -> Result e b -> Result e b

(<*) :: Result e a -> Result e b -> Result e a

Functor (Result e)

Defined in ConditionalRestriction.Result

Methods

fmap :: (a -> b) -> Result e a -> Result e b

(<$) :: a -> Result e b -> Result e a

Monad (Result e)

Defined in ConditionalRestriction.Result

Methods

(>>=) :: Result e a -> (a -> Result e b) -> Result e b

(>>) :: Result e a -> Result e b -> Result e b

return :: a -> Result e a

(Show e, Show a) => Show (Result e a)

Defined in ConditionalRestriction.Result

Methods

showsPrec :: Int -> Result e a -> ShowS

show :: Result e a -> String

showList :: [Result e a] -> ShowS

(Eq e, Eq a) => Eq (Result e a)

Defined in ConditionalRestriction.Result

Methods

(==) :: Result e a -> Result e a -> Bool

(/=) :: Result e a -> Result e a -> Bool

type ErrorMsg = String

Plain text error message.